Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Not applicable (Common wild type)
Hardiness Zones
USDA Zones 2-11 (as an annual); germinates when soil temperatures reach 55°F; killed by the first hard frost in autumn.
About This Grass
A low-growing, spreading annual weed. It features pale to dull green stems that can turn purplish with age. In unmatched states, it produces finger-like racemes (seed heads) that emerge from the top of the stalk in a Digitaria (finger-like) arrangement.
Blade Characteristics
Coarse blade width (5-10mm); flat shape with a pointed tip; light green to medium green color; rolled vernation in the bud. Notable for having prominent hairs (trichomes) on both the leaf blades and the sheaths. Ligule is membranous; auricles are absent.
Root System
Shallow, fibrous root system; aggressive establishment speed through both seed and the rooting of stem nodes (stolons). Does not form a permanent sod but creates dense seasonal mats.
Growing Information
Origin Region
Native to Europe and Asia; highly invasive and naturalized throughout North America and temperate/tropical regions globally.
Growth Habit
Stoloniferous and decumbent (prostrate); stem nodes roots upon contact with soil, forming dense, multi-branched mats.
Sunlight & Water Needs
Full sun preferred (very opportunistic); high drought tolerance once established; thrives in compacted or poor soils with frequent watering but manages well in dry waste areas; pH adaptable (5.5 to 7.5).
Mowing & Maintenance
Extremely low mowing tolerance; it can set seed even when mowed as low as 0.5 inches. In lawn care, maintenance involves pre-emergent herbicides in early spring and maintaining thick turf to prevent light from reaching crabgrass seeds.
Special Characteristics
High traffic tolerance; prolific seed producer (up to 150,000 seeds per plant); allelopathic tendencies that can inhibit the growth of neighboring desirable grasses; excellent heat tolerance.
Ecological Information
Invasive status in lawns and agricultural fields; provides some forage value for livestock and seeds for ground-feeding birds, but generally considered a nuisance that displaces native species and uniform turfgrasses.